Sewing machine lubrication systems



Dec. 9, 1958 J. G. ATTWOOD ETIAL 2,863,412

SEWING MACHINE LUBRICATION SYSTEMS Filed Dec. 9, 1954 6 Sheets-Sheet 11958 J..G. ATTWOOD ET AL 2,863,412

SEWING MACHINE LUBRICATION SYSTEMS 6 Sheets-Sheet 2 Filed Dec. 9, 19549, 1958 J. G. ATTWOOD ETAL SEWING MACHINE LUBRICATION SYSTEMS 6 S heets-Sheet 3 Filed Dec 9, 1954 1958 J.'G. ATTWOOD ETAL 2,863,412 SEWINGMACHINE LUBRICATION SYSTEMS 6 Sheets-Sheet 4 7 Filed Dec. 9, 1954 1958J. a. ATTWOOD ET AL 2,863,412

SEWING MACHINE LUBRICATION SYSTEMS Filed Dec. 9. 1954 6 Sheets-Sheet 5Dec. 1958 J. G. ATTWOOD ET AL 2,863,412

SEWING MACHINE LUBRICATION SYSTEMS 6 Sheets-Sheet 6 Filed Dec. 9. 1954United States Patent SEWING MACHINE LUBRICATION SYSTEMS John G. Attwood,Oak Park, 'Clarence C. Smith, Chicago, and John N. Covert, Park Forest,Ill., assignors to Union Special Machine Company, (Ihicago, 111., acorporation of Illinois Application December 9, 1954, Serial No. 474,14213 Claims. (Cl. 112--256) This invention relates to improved lubricatingsystems for sewing machines and more particularly to devices fordelivering a limited, predetermined amount of lubricant to a specificpoint, such as the raceway of a rotary hook.

Heretofore various schemes have been proposed for the delivery ofprecise amounts of lubricant to various bearing surfaces of a sewingmachine and particularly the raceway of a rotary hook. A special problemis presented by sewing machines in the way of delivering an adequateamount of lubricant to various surfaces which are not fully enclosed,without delivering an excess which will be thrown by the rapidly movingparts. The raceway of a rotating hook element poses an especiallydifficult problem because of the high speed of rotation of the hook andthe tendency to throw oil onto the stitch ing threads, or even throughthe openings in the throat plate onto the work being stitched. Schemesheretofore employed for regulating or controlling the supply oflubricant to a hook raceway, prior to the present invention, haveusually involved a needle valve or the like in the path of delivery ofthe lubricant to the raceway or a valve of some character in a lubricantby-pass arranged to regulate the amount of lubricant delivered to thehook raceway by directing a greater or lesser amount of the totallubricant being pumped to the bypass which serves to return the excesslubricant to the reservoir from which it is drawn. While thesearrangements have proved reasonably satisfactory, they have not fullymet the reguirements due to the difficulty of regulating the controlvalve in a way to insure delivery of the optimum amount of lubricant tothe raceway for different speeds of operation of the machine and othervariable conditions encountered. Moreover, the operation of such systemshas been adversely affected by the presence of lint or other foreignparticles in the lubricant Another control means which has heretoforebeen suggested is the provision of a porous plug or the like in the lineof transmission of the lubricant but this has been subject to thedifficulty of accurately and uniformly providing such plugs withprecisely the desired lubricant transmitting properties and due to theunavoidable variation in the action of such elements as a result ofclogging with particles of dirt.

A primary object of the present invention has been to provide anarrangement for regulating or controlling the delivery of lubricant to ahook raceway, or other surfaces having the same type of preciselubrication requirements, which is reliable in its action overlongperiods of time and for varying conditions of operation of themachine.

An important feature of the invention is the provision of means forregulating the delivery of lubricant to a hook raceway or the like whichdepends for its control upon the variation in effective length of aporous capil-' lary delivery element. Such means have been found todeliver, when properly regulated, the small amounts of 2,863,412Patented Dec. 9, 1958 ly and finely controlled amount of lubricant tothe surface to be lubricated.

In the preferred embodiment of the invention there is provided a rotarycontrol member of porous, capillary character arranged for adjustmentfrom a readily accessible point to vary the length of travel of thelubricant fro-m the point of delivery of the lubricant to the member tothe point of removal of the lubricant, by a suitable pumping means, fordelivery to the surface requiring lubrication. Preferably the deliveryof lubricant to the rotary control member is achieved through theprovision of a porous wick-like element which has one end immersed inlubricant in a reservoir and serves to lift lubricant from the reservoirby capillary action and to deliver the lubricant to the periphery of therotary member, by contact therewith, at a point determined by theadjustment of the latter. The wick-like element is preferably of looserconstruction or of greater porosity than the control member and isadapted to deliver lubricant at a faster rate than it is normallytransmitted through the porous control member. In lifting the lubricantthe wick-like element functions as a filter to prevent the transmissionto the control member of lint and other foreign matter.

The pump means which picks up the lubricant from the control member andforces it to the hook raceway, or other surface requiring lubrication,is responsive to the speed of operation of the machine and serves toincrease or decrease the rate of transmission of the lubricant throughthe control member, at a particular setting of the latter, in accordancewith the speed of operation of the machine.

A special feature of the preferred arrangement is the provision ofmanually operable means for disengaging the wick element from the rotarycontrol .member when the latter is being adjusted from one setting toanother. This serves to eliminate wear and tear upon the cooperatingsurfaces of the wick element and the rotary control member. It alsofacilitates accurate adjustment of these parts.

Other objects, advantages, and special features of the new lubricationsystem will be discussed in connection with the detailed description ofcertain illustrative forms of the invention which will now be given inconjunction with the accompanying drawings, in which:

Fig. l is a vertical longitudinal sectional view through a lockstitchsewing machine embodying the invention;

Fig. 2 is a bottom plan view of the machine with portions removed orbroken away;

Fig. 3 is a View, partly in elevation and partly in vertical sectiontaken along the line 3-3 of Fig. 2, showing the rotary hook and thedriving connections and lubrieating means therefor;

Fig. 4 is a transverse vertical sectional view through the machine takenalong the line 4-4 of Fig. 3;

Fig. 5 is a detail view, in perspective, of a retainer element for aporous lubricant delivery element embodied in the machine;

Fig. 6 is an exploded perspective view of the parts forming theregulating means for the delivery of lubricant to the rotary hook;

Fig. 7 is a perspective view of a sub-assembly of certain of the partsshown in Fig. 6;

Fig. 8 is an end view of the hook shaft, as seen from the right in Fig.3;

Fig. 9 is an enlarged axial sectional view through the of Fig. 8, thetaper of the bore therein being indicated on an exaggerated scale;

Fig. is an end View of the hook shaft showing a modified form oflubricant impelling groove therein;

Fig. 11 is a transverse sectional view through the lubricant reserviorand associated parts, taken along the line 1111 of Fig. 2;

Fig. 12 is a detail view, in axial section through the means forregulating the delivery of lubricant to the hook shaft;

Fig. 13 is a face view of a pressure disc forming part of the assemblyof Fig. 12 as seen from the right in Fig. 12;

Fig. 14 is a face view of an adjusting element for the lubricant flowregulating means and certain associated de vices;

Fig. 15 is a view similar to Fig. 11 showing a modified arrangement foradjusting the flow regulating means;

Fig. 16 is a detail view, in elevation of a modified form of porousmember; and

Figs. 17 and 18 are detail views, in perspective, of modified forms ofwick elements.

The invention has been illustrated as applied to a lockstitch sewingmachine of the general character illustrated in the patent to George M.Reimer, No. 2,643,625, granted June 30, 1953. It has a frame comprisingwork supporting base 11 a vertical standard 11, and an overhanging arm12 terminating in a needle head 13. A main operating shaft 14 extendslongitudinally through the overhanging arm and terminates at one endwithin the needle head and at its opposite end outwardly of the vertical standard of the frame. It is journaled in suitable bearings providedin the vertical standard and in a partition wall separating the mainportion of the overhanging arm from the needle head. A combinedhandwheel and pulley 15 is secured to the shaft at the end thereof whichextends outwardly from the vertical standard.

Within the needle head, the shaft 14 carries a crank member 16 having aneccentrically disposed element 17 which is connected by a link 18 with aneedle bar 19. The latter carries at its lower end a needle 20 which,upon rotation of the shaft 14, is carried repeatedly from a positionabove the work support to a position in which its thread carrying eye isbeneath the work support. Cooperating with the needle inthe formation oflockstitches is a rotary hook 21 (Figs. 2 and 3) which is secured to theend of a hook shaft 22 journaled in a bearing sleeve 23 carried by thebase portion of the frame. It will be understood that the hook 21 has arotary component which is rotated by the shaft and a stationarycomponent, in the form of a bobbin case holder, which is held againstrotation by means of a retainer 24 carried by the base portion of theframe. The present invention is concerned primarily with the means forinsuring the delivery of a small, closely regulated amount of lubricantto the bearing surfaces between the rotary component and the stationarycomponent of the hook. These bearing surfaces are conventionally in theform of a raceway provided in the rotary component and a rib projectingradially from the stationary component or bobbin case.

The hook shaft 22 extends through a small lubricant reservoir 25 andprojects some distance beyond the latter toward the right in Fig. 3.Within the reservoir 25 there is secured to the shaft 22 a pinion 26which meshes with a gear 27 carried by a rotary drive shaft 28 journaledin suitable bearings within the base portion of the frame. Shaft 28extends through the lubricant reservoir 25 and to some distance beyondthe left wall thereof (Fig. 2). This shaft is driven from the shaft 14by gearing 29 within the vertical standard. The two shafts 14 and 28 aredriven at the same angular speed but the gearing 26, 27 is such that thehook shaft is driven at twice this angular speed.

Cooperating with the stitch forming devices in the formation of a seamis any suitable form of work feeding mechanism which, as illustrated,may conveniently comprise a four-motion feed dog (not shown) driven fromthe shaft 28. Since the details of this mechanism form no part of thepresent invention it is believed unnecessary to describe it fully.Suflice itto say that the feed dog is carried by a feed bar 30 (Fig. 2)which is given lifting and lowering movements by means of an eccentricat the left end of the shaft 28 and is given feed and return movementsby connections from the shaft 28 of the general character disclosed inthe above mentioned patent to Reimer. As there disclosed, adjustment ofthe feed stroke may be effected by adjusting a variable eccentric 30a(Fig. 1) carried by the shaft 28 acting through a pitman 30b (Fig'. 2)upon a feed rocker 3110. A presser foot 31 (Fig. 1) carried by a presserbar vertically disposed in the needle head, and spring urged downwardlyin a known manner, cooperates with the work and with the feed dog toinsure proper advance of the work.

Turning now to the means for lubricating the raceway of the rotary hook,in accordance with the invention, there is provided a lubricantreservoir 32 (Figs. 1, 2, 3, and 4) which is suitably secured to theunderface of the work supporting portion of the base of the frame. Thisreservoir carries lubricant to a desired level, such as that indicatedin Fig. 3. The lubricant may be introduced into the reservoir byremoving a screw plug 33 accessible at the top of the work support ofthe base. To enable the operator to determine readily the level of thelubricant in the reservoir a transparent plug 34, formed preferably ofLucite, is suspended from the top of the reservoir and has its upper endvisible through an opening in the work support. The lower end of thisplug has one face inclined, as indicated in Fig. 3, and this face isprovided with score lines 35 and 36 indicating, respectively, themaximum and minimum levels for the lubricant Within the reservoir.Within a narrow extension 37 at the left end of the reservoir 32 (Figs 2and 4) there is positioned a porous wick element 38 of relatively looseconstruction arranged to lift lubricant by capillary action. This wickelement extends through an opening 39 at the top right hand corner (Fig.4) of the extension 37 and is suitably folded over the end of a springmember 40. The latter has an extension thereof secured to the reservoirby means of screws 41 and preferably has a finger piece 42 by which itmay be rocked downwardly and toward the right in Fig. 4. A retaining orclamping element 43, illustrated in detail in Fig. 5, extends along aportion of the surface of the wick 38 and outwardly through the opening39 in the extension 37 of the reservoir. The outer end 44 of thisclamping element is pointed or spearshaped and is passed through thewickin g and through an opening in the spring element 41 and then bentover, as shown in Fig. 4, to retain the wick in fixed relation to thespring element. 1

Spring element serves to urge the folded portion 38a of the wickingagainst the periphery of a circular portion 45 of a porous member formedof felt or oilite or the like adapted, by capillary action, to convey toa further point the lubricant which is delivered to it by means of thewicking 38. The circular portion 45 of the porous member does notdescribe a complete circle but extends through an angle of about 330.One end is free and the other end has a radially inwardly extendingportion 46 carrying at its inner end a smaller circular portion 47having a relatively tight bearing fit in relation to the hook shaft 22.To retain the porous member in the shape shown in Fig. 4 and hold itagainst rotation with the shaft 22, it is carried by a support 4 5preferably formed of steel, or other metal, bent into the shapeindicated. The porous member is preferably adhesively secured to thesupport member 48 with the portion 45 of the porous member surroundingthe outer face of the support member and the portion 47 of the porousmember fitting between the shaft 22 and the inner surface 50 of thesupport member 48 to which it is also adhesively secured. Portions 45and 47 of the porous member are spaced radially in relation to eachother to provide a QQQSAIQ channel 49 for the insertion of the supportmember ea. As shown, the latter does not describe a completecircumference 'but provides, between the free ends of itscircumferentially extending portion, an opening. 51 through which theportion 46 of the porous member may extend radially inward. A disc 52,preferably formed of steel or other metal is inserted Within the supportmember 48 and firmly secured thereto by soldering or the like to theinner surface 50 of the support member.

Suitable means are provided for exerting an axial pressure against thedisc 52 to force this yieldingly against the end of the hook shaft 22,as best shown in Fig. 12. For this purpose the disc 52 is provided witha conical or spherical depression 53 at its center arranged to receivethe nose of a spring urged plunger or pin 54. The latter is slidablewithin an axial opening or bore 55 in an adjustable shaft 56. A spring57 interposed between the pin 54 and the inner end of the opening 55serves to urge the pin and the disc 52, together with the support member48 and porous member 45, 47, toward the left (Fig. 12).

At its end adjacent the disc 52 the shaft 56 has a radially extendingflange 58 which has an eccentrically disposed pin 59 extending throughit and projecting from the opposite faces of the flange. That partprojecting toward the disc 52 cooperates with a notch 60 in the opposedface of the latter so that any turning movement imparted to the shaft 56is transmitted to the disc 52. Shaft 56 has a spirally toothed portion61 at its end within the extension 37 of the reservoir and this toothedportion cooperates with a worm or screw-threaded formation 62 on a bolt63 extending transversely across the portion 37 of the reservoir andsuitably journaled therein. The head of the bolt has a slot 64 adaptedto receive a screwdriver or the like for turning the bolt and therebyturning the shaft 56. It will 'be understood that this will bring aboutrotation of the disc 52, support member 48 and porous member 45, 47 ineither a clockwise or counter clockwise direction (Fig. 4). When thecontrol unit is thus being turned the finger piece 42 of the spring arm40 may be depressed to disengage the nose 38a of the wicking from theportion 45 of the porous member. By suitable adjustment of the porousmember in this manner, the point along the outer surface of the portion45 of the member which is engaged by the nose 38a of the wick element 38may be adjusted as desired. Such adjustment will vary the rate ofdelivery of lubricant from the wick element to the central portion 47 ofthe porous member. The path of travel of the lubricant circumferentiallyalong the portion 45 of the porous member in a clockwise direction tothe radially inwardly extending portion 46 will be varied and thuseither increase or decrease the overall resistance to flow and hence therate of delivery of the lubricant. To limit the extent of rotation ofthe shaft 56 and connected parts a stop screw 59a extends from theadjacent face of the lubricant reservoir into the path of that end ofpin 59 which projects toward the reservoir. This is to guard againstturning of the porous member 45 into a position in which the nose 38would fall into the opening between the free end of the portion 45 ofthe porous member and the radially extending portion 46 thereof.

The lubricant delivered to the central portion 47 of the porous memberis picked up by the cooperating face of the pressure disc 52 and is thenpumped from that face to the bore of the hook shaft 22 by means of aspiral groove 65 formed in the end face of the shaft 22. The directionof rotation of the shaft is indicated by the arrow in Fig. 8. In pumpingthe lubricant into the bore of the shaft, the groove tends to draw thelubricant more rapidly through the portion 45 of the porous member, andthis tendency increases with the speed of the shaft so that the systemthus keeps up with the greater requirements of lubricant at higherspeeds. The rate of trans mission of lubricant, however, is at all timesinversely proportional, though not as a straight line function, to thelength of the path of travel of the lubricant through the porous controlmember. By appropriately varying the -cross-sectional area of theportion 45 of the porous member a straight line relationship betweenlength of path and rate of delivery could be obtained, if desired.

In lieu of the spiral groove shown in Fig. 8 there may be provided astraight groove a (Fig. 10) which extends tangentially from the bore ofthe shaft. However, the spiral form is preferred. It should beunderstood that in lieu of providing the groove in the end of the shaft22 the latter may be plain and a corresponding groove may be formed inthe cooperating face of the pressure disc 52 in the area engaged by theend of the shaft. Such a groove would extend in the reverse directionfrom that provided in the end of the shaft. Two or more grooves could beprovided in the end face of the shaft or in the cooperating surface ofdisc 52, if desired.

To provide a squeezing action upon the central portion 47 of the porousmember and thus urge the inner wall surrounding the central openingthereof into engage-- ment with the shaft 22, there is provided a ring66 having a flange 67 arranged to receive one end of a light spring 68,the opposite end of which abuts against a bushing 69 forming a bearingfor the shaft 22. Spring 68 urges the ring 66 toward the right (Fig. 12)and by means of 'an annular rib 70 on the right face thereof serves toprovide the squeezing action mentioned. Spring 68, it will beunderstood, exerts a lighter pressure than the spring 57 and thuspermits the latter to hold the porous regulating assembly against theend of the hook shaft in the manner explained.

Lubricant which is delivered to the bore 22a of the hook shaft isadvanced along the latter toward the left (Figs. 2 and 3) and isdelivered to a chamber 71 formed in the hook body from which it passesthrough a radially extending channel 72 and a channel 73, parallel withthe axis of the hook, to the raceway of the latter. To facilitate andspeed up the movement of the lubricant through the bore of the hookshaft the latter is preferably flared slightly from its right end towardits left end so that the diameter of the bore is greater at the left endthan at the right. Within the bore of the hook shaft there is preferablyprovided a wick element '74 bent upon itself, in the manner shown inFig. 3, and preferably stiffened by a wire core. This Wick elementcoupled with the flare of the bore serves to retain a small amount oflubricant within the hook shaft and prevents its return by syphoh actionto the reservoir 32 when the machine is at rest. it has been found thatwithout the wick element 7 it requires a period of 10 seconds to bringabout delivery of lubricant to the raceway after the machine has beenidle for a substantial period of time so that the bore of the hook shaftis substantially dry. This is even with the tapered formation of thebore of the shaft. If a non-tapered bore is provided this time factor isas much as 30 seconds. While this delay may not be serious, it isconsidered preferable to eliminate it and the arrangement disclosed,including the tapered bore and the provision of the wick element 74,serves to bring about substantially immediate delivery of lubricant tothe hook raceway even after the machine has been idle for a substantialperiod.

While it should be understood that the invention is not limited to theparticular dimensions and other details to be hereinafter specified, ithas been found that a lubricant delivery and control system for ahorizontal hook having the following characteristics is particularlyeifective. The hook shaft in the illustrative example has an outsidediameter of .319 of an inch and is 4.45 inches long. its bore has adiameter of of an inch at its smaller end and flares at the rate of /4inch per foot toward its discharge end within'the hook. The pressuredisc 52 has an outside diameter-M1562 of an inch. Support member 48 hasan outside'diameter of inch and an inside diameter of .562 inch. Thethickness of the metal of which the support member is formed is .028inch and its axial width is inch. Portion 45 of the porous controlmember has a radial thickness of /8 inch and a width of A5 inch. Portion47 of the porous member has an outside diameter of V of an inch and anopening at its center of .312 inch. This porous member is formed of ahard felt and is of denser construction than the wicking 38. A highlysatisfactory porous member has been formed of inch American Felt Co. No.7544; this conforms with the specifications for S. A. E. F1 felt. It isa relatively dense felt formed largely of wool. The wicking may also beformed of a strip of felt and may have a width of of an inch and athickness of /8 of an inch. It may be formed of S. A. 13. P40 felt, suchas sold by the American Felt Co. under No. 51018. This is likewiseformed largely of wool but is of little more than half the density of S.A. E. ll felt. Sealing ring as has a maximumdiameter of .370 inch and anoutside diameter of .430 inch. This ring not only serves to urge theportion 47 of the porous member into engagement with the shaft 22 butalso holds to a minimum the entry of air to the porous member and itsdelivery to the bore of the hook shaft.

In lieu of having the portion 45 of the porous member of uniform radialthickness and uniform width the member may be provided with theconfiguration illustrated in Fig. 16. As there shown, the portion 45a ofthe porous member varies in radial thickness from its free end towardits junction with the portion 46. It is of greatest thick ness at itsmid-portion and tapers oif toward its free end toward its junction withthe portion 46a. If desired the modified porous element could vary inwidth instead of, or in addition to, the indicated variation in radialthickness. The important thing is to vary the cross-sectional areathrough the portion 45a at different points along its length. It shouldbe understood that this variation in cross-sectional area may bemodified in any suitable way to achieve a desired control over the rateof flow of the lubricant. If desired, it may be such as to provide astraight line relationship between the rate of delivery of lubricant andthe length of the portion 45 of the porous member through which thelubricant travels to the radial portion 46. Or the arrangement may besuch as to increase substantially the overall variation in the rate offlow. if the portion 45 of the porous member is of uniformcross-sectional area, as indicated in Figs. 4 and 6, the rate of flow ofthe lubricant may vary as much as 10 to l as between the fastest andslowest rates of delivery. However, by suitable variation incross-sectional area of the control portion of the porous member, avariation in the rate of flow of as much as 30 to 1 may be achieved.

A more porous or less dense felt than the S. A. E. F-lO may be used forthe wicking 3-8, if desired, and when this is done the variation in therate of delivery of lubricant, due to variation in the height of thelubricant in the reservoir is less. The overall variation in the rate ofdelivery due to the difference in height of the lubricant in thereservoir may be held to not more than 5%. If the wicking is formed ofS. A. E. F-lO felt, the overall variation in the rate of delivery of thelubricant may be several times higher than this as the level of thelubricant in the reservoir changes. However, to reduce this variation inrate of delivery to a minimum, the portion of the wicking which isimmersed in the lubricant within the reservoir may be of increasedcross-sectional area, as indicated in Figs. 17 and 18. As shown in Fig.17 the wicking 355a. may have a laterally extending portion 38y which isimmersed in the lubricant in the reservoir. In Fig. 18 the wicking 38bis shown as provided with one or more added sections of felt 38z whichserves to increase the overall cross-sectional area of the portion whichis immersed in the lubricant. With either of these arrangements theoverall variation in rate of delivery due to changes in the level of thelubricant in the reservoir may be held to about 5%.

In Fig. 15 there is shown a modified arrangement in which the adjustingbolt for the lubricant control unit is accessible from the top of thecloth plate or work supporting base of the frame instead of from thefront of the latter. Aside from the arrangement of the adjusting meansfor the control unit the construction shown in Fig. 15 is the same asthat hereinabove described and the various parts which have not beenmodified are identified by the same reference characters. The adjustingmeans comprises a bolt which is vertically disposed and has a screwthread or spiral formation 75 at its lower end cooperating with thespiral teeth 61 of the control unit. Enlarged head 76 of the bolt,provided with a slot 77 to receive a screw driver, extends into an opening 78 in the work supporting surface of the base 10 of the frame.Preferably the top of the bolt is flush with or slightly below the levelof the work supporting surface. To retain the bolt against axialmovement as it is turned, a screw 79 is provided, this having a reducedstem at its inner end cooperating with an annular groove 80 extendingaround the body of the bolt. If desired the screw 79 may be arranged toclamp the bolt against turning after it has been adjusted. However, thisis not necessary.

'It is believed that the mode of operation of the new lubricant controlsystem will be clear from the foregoing detailed description so that arsum of its operation is unnecessary. Certain distinct advantages of thesystem include the accurate and minute control over the rate of deliveryof the lubricant from the reservoir to the hook raceway or the surfaceto be lubricated. At the same time the spiral groove pumping meansprovided in the unit serves to increase the rate of delivery of oil asthe speed of the machine increases and its requirements for lubricationcorrespondingly increases. The pumping means disclosed is capable ofdeveloping a pumping head of at least 6 inches so that changes in theheight of the lubricant in the reservoir will have very little, if any,effect upon the rate of flow. Any lint or other dirt in the lubricantwithin the reservoir is filtered out in the course of lifting it by thecapillary action of the wicking 38. The system cannot become air-lockedin view of the arrangement of the disc 52 and the sealing ring 66. Byappropriate shaping and arrangement of the porous control member 45, 47the rate of flow of lubricant can be made directly proportional, i. e.as a straight line function, to the number of turns applied to theadjusting bolt 62. However, to provide an indication of the adjustmentof the unit, and thus facilitate its readjustment, the peripheralsurface of the flange 58 may, if desired, be provided with indicia. 'Itmay be viewed in relation to an index mark suitably located on the frontsurface of the reservoir 32 or at the edge of an opening through thework supporting surface of the base portion of the frame just above theflange 53. A suitable transparent disc may be provided within such anopening to close the same, if employed.

The control unit provides a very uniform rate of delivery of thelubricant at any particular setting. At the same time the constructionof the unit is such that no very close tolerances are required in theproduction of any of the parts. The metering of the lubricant isachieved at a point quite removed from the surfaces tending to generateheat, so that it is not affected to any great extent by changes inviscosity of the oil due to.

heating up of portions of the machine.

While a preferred embodiment of the invention and certain modificationsthereof have been described in considerable detail, it will beunderstood that other changes may be made in the construction andarrangement of the several parts within the scope of the appendedclaims.

What'is claimed is:

1. In a sewing machine a bearing surface requiringa precise amount oflubricant for most effective operation, means for delivering lubricantto said bearing surface which comprises a porous lubricant conductingmember having a predetermined fixed porosity adapted to convey lubricantby capillary action, said member providing a path of variable length oftransmission of lubricant, the length of said path determining the rateat which the lubricant is delivered, means for delivering lubricant tosaid member atone point along its length of transmission, pump means forreceiving said lubricant from said member at a second point along itslength of transmission and arranged to deliver the lubricant at adesired rate to said bearing surface only during operation of themachine, and means for shifting said=member in relation to at least oneof said two last-mentioned means to vary the distance between said twopoints and thereby vary the length of said path through which saidlubricant must be transmitted through said member from said first pointto said second point.

2. in a sewing machine a bearing surface requiring a precise amount oflubricant for most effective operation, means for delivering lubricantto said bearing surface which comprises a porous lubricant conductingmember adapted to convey lubricant by capillary action, said memberproviding a path of variable length of trans mission of lubricant, thelength of said path determining the rate at which the lubricant isdelivered, capillary means for delivering lubricant to said member atone point along its length of transmission, pump means for receivingsaid lubricant from said member at a second point along its length oftransmission and operative only during operation of the machine fordelivering the lubricant at a desired rate to said bearing surface, andmeans for varying the relationship between said member and at least oneof said two last-mentioned means to vary the distance between said twopoints and thereby vary the length of said path through which saidlubricant must be transmitted through said member from said first pointto said second point Without varying the porosity of said lubricantconducting member.

3. In a sewing machine a bearing surface requiring a precise amount oflubricant for most effective operation, means for delivering lubricantto said bearing surface which comprises a porous lubricant conductingmem ber adapted to convey lubricant by capillary action, said memberproviding a path of variable length of transmission of lubricant, saidmember having a circularly disposed lubricant receiving portion and aradially extending delivery portion adjacent one end of said circularlydisposed portion, means for delivering lubricant to said member at onepoint along said circularly disposed portion, means for receiving saidlubricant from said member at said delivery portion and delivering saidlubricant to said bearing surface, and means for varying thecircumferential location of said one point along said circularlydisposed portion.

4. In a sewing machine a bearing surface requiring a precise amount oflubricant for most effective operation, means for delivering lubricantto said bearing surface which comprises a porous lubricant conductingmember adapted to convey lubricant by capillary action,said memberproviding a path of variable length of transmission of lubricant, saidmember having a circularly disposed lubricant receiving portion and aradially extending delivery portion adjacent one end of said circularlydisposed portion, means for delivering lubricant to said member at onepoint along said circularly disposed portion, means for receiving saidlubricant from said member at said delivery portion and delivering saidlubricant to said bearing surface, said last mentioned means comprisinga disc havin a radially disposed surface in contact with said deliveryportion of saidmember and arotatable hollow shaft having a surface atone end thereof'in contact with It? said surface of said disc, one ofsaid contacting surfaces of the disc and shaft being provided with agroove arranged to force oil into the interior of said shaft .uponrelative rotation of said shaft and disc, and means for varying thecircumferential location of said one point along said circularlydisposed portion.

5. in a sewing machine having stitch forming devices including a rotaryhoolcwith a rotary component and a stationary component, said hookhaving a raceway in one of said components cooperating with a rib on theother of said components, and a horizontally extending rotary shaftcarrying said rotary component and having an axially extending bore incommunication with said raceway, the combination of means for supplyinglubricant to said bore of said shaft for delivery to said raceway whichcomprises a lubricant reservoir carrying lubricant at a level whollybelow said shaft, a stationary porous element arranged for delivery oflubricant by capillary action to a point adjacent the free end of saidshaft, said element providing a path of variable length for transmissionof said lubricant, means rotatable with said shaft for forcing thelubricant so delivered by said porous element into the bore of saidshaft upon rotation thereof, means for delivering lubricant from saidreservoir to a point along said porous element, said last mentionedmeans comprising a wick element of greater porosity than said porouselement, and means for varying the location of the point along saidelement at which said lubricant is so delivered to thereby vary thelength of the path of travel of the lubricant through said porouselement to the free end of said shaft without altering the porosity ofsaid porous element.

6. in a sewing machine having stitch forming devices including a rotaryhook with a rotary component and a stationary component, said hookhaving a raceway in one of said components cooperating with a rib on theother of said components, and a horizontally extending rotary shaftcarrying said rotary component and having an axially extending bore incommunication with said raceway, the combination of means for supplyinglubricant to said bore of said shaft for delivery to said raceway whichcomprises a lubricant reservoir carrying lubricant at a level whollybelow said shaft, a stationary porous element arranged for delivery oflubricant by capillary action to a point adjacent the free end of saidshaft, said element providing a path of variable length for transmissionof said lubricant, means rotatable with said shaft for forcing thelubricant so delivered by said porous element into the bore of saidshaft upon rotation thereof, means for delivering lubricant from saidreservoir to a point along said porous element, and means for varyingthe location of thepoint along said element at which said lubricant isso delivered to thereby vary the length of the path of travel of thelubricant through said porous element to the free end of said shaftWithout altering the porosity of said porous element, the bore of saidshaft having a slight outward taper from the free end of the shafttoward the opposite end thereof to facilitate movement of the lubricanttoward said opposite end.

7. In a sewing machine having stitch'forming devices including a rotaryhook with a rotary component and a stationary component, said hookhaving a raceway in one of said components cooperating with a rib on theother of said components, and a horizontally extending rotary shaftcarrying said rotary component and having an axially extending bore incommunication with said raceway, the combination of means for supplyinglubricant to said bore of said shaft for delivery to said raceway whichcomprises a lubricant reservoir carrying lubricant at a level Whollybelow said shaft, a stationary porous element arranged for delivery oflubricant by capillary action to a point adjacent the free end of saidshaft, said element providing a path of variable length for transmissionof said lubricant, means rotatable with said shaft for forcing thelubricant so delivered by said porous element into the bore of saidshaft upon rotation thereof, a wick element within said bore of theshaft for retaining lubricant thereinwhen the machine is idle, means fordelivering lubricant from said reservoir to a point along said porouselement, and means for varying the location of the point along saidelement at which said lubricant is so delivered to thereby vary thelength of the path of travel of the lubricant through said porouselement to the free end of said shaft without altering the porosity ofsaid element.

8. In a sewing machine having stitch forming devices including a rotaryhook with a rotary component and a stationary component, said hookhaving a raceway in one of said components cooperating with a rib on theother rotary component and having an axially ext in communication withsaid raceway, ti c comb 1 means for supplying lubricant to said here ofsaidshaft for delivery to said raceway which comprises a lubricantreservoir carrying lubricant at a level below said shaft, a stationaryporous element arranged for delivery of lu-- bricant by capillary actionto a point adjacent the free end of said shaft, said element providing apath of variable length for transmission of said lubricant, meansrotatable with said shaft for forcing the lubricant so delivered by saidporous element into the bore of said shaft upon rotation thereof, a wickelement within said bore of the shaft for retaining lubricant thereinwhen the machine is idle, said wick element only partially filling saidbore and providing a passage along the surface of said bore for thedelivery of lubricant along said surface, means for delivering lubricantfrom said reservoir to a point on said porous element, and means forvarying the location of the point at which said lubricant is sodelivered to thereby vary the length of the path of travel of thelubricant through said porous element to the free end of said shaft.

9. In a sewing machine having stitch forming devices including a rotaryhook with a rotary component and a stationary component, said hookhaving a raceway in one of said components cooperating with a rib on theother of said components, and a rotary shaft carrying said rotarycomponent and having an axially extending bore in communication withsaid raceway, the combination of means for supplying lubricant to saidbore of said shaft for delivery to said raceway which comprise alubricant reservoir carrying lubricant at a level below said shaft, astationary porous element arranged for delivery of lubricant bycapillary action to a point adjacent the free end of said shaft, saidelement providing a path of variable length for transmission of saidlubricant, means rotatable with said shaft for forcing the lubricant sodelivered by said porous element into the bore of said shaft uponrotation thereof, a wick element within said bore of the shaft forretaining lubricant therein when the machine is idle, said wick elementonly partially filling said bore and providing a passage along thesurface of said bore for the delivery of lubricant along said surface,the bore of said shaft having a slight outward taper from the free endof said shaft toward the opposite end thereof to facilitate movement ofthe lubricant toward said opposite end, means for delivering lubricantfrom said reservoir to a point on said porous element, and means forvarying the location of the point at which said lubricant is sodelivered to thereby vary the length of the path of travel of thelubricant through said porous element to the free end of said shaft.

10. In a sewing machine having stitch vforming devices including arotary hook with a rotary component and a stationary component, saidhook having a raceway in one of said components cooperating with a ribon the other of said components, and a rotary shaft carrying said rotarycomponent and having an axially extending bore in communication withsaid raceway, the combination of means for supplying lubricant to saidbore of said shaft for delivery to said raceway which comprises alubricant reservoir carrying lubricant at a level below said shaft, astationary porous element arranged for delivery of lubricant bycapillary action to a point adjacent the free end of said shaft, saidelement providing a path of variable length for transmission of saidlubricant, means rotatable with said shaft for forcing the lubricant sodelivered by said porous element into the bore of said shaft uponrotation thereof, means for delivering lubricant from said reservoir toa point on said porous element, said last mentioned means comprising awick element of greater porosity than said porous element, resilientmeans for urging said wick element yieldingly against said porous element, and means for varying the location of the point at which saidlubricant is so delivered to thereby vary the length of the path oftravel of the lubricant through said porous element to the free end ofsaid shaft.

11. In a sewing machine having stitch forming devices including a rotaryhook with a rotary component and a stationary component, said hookhaving a raceway in one of said components cooperating with a rib on theother of said components, and a rotary shaft carrying said rotarycomponent and having an axially extending bore in communication withsaid raceway, the combination of means for supplying lubricant to saidbore of said shaft for delivery to said raceway which comprises alubricant reservoir carrying lubricant at a level below said shaft, astationary porous element arranged for delivery of lubricant bycapillary action to a point adjacent the free end of said shaft, saidelement providing a path of variable length for transmission of saidlubricant, means rotatable with said shaft for forcing the lubricant sodelivered by said porous element into the bore of said shaft uponrotation thereof, means for delivering lubricant from said reservoir toa point on said porous element, said last mentioned means comprising awick element of greater porosity than said porous element, resilientmeans for urging said wick element yieldingly against said porouselement, manually operable means for disengaging said wick element fromsaid porous element, and means for shifting said wick element and saidporous element relative to each other while so disengaged to vary thelocation of the point at which said lubricant is delivered to saidporous element to thereby vary the length of the path of travel of thelubricant through said porous element to the free end of said shaft.

12. In a sewing machine having stitch forming devices including a rotaryhook with a rotary component and a stationary component, said hookhaving a raceway in one of said components cooperating with a rib on theother of said components, and a rotary shaft carrying said rotarycomponent and having an axially extending bore in communication withsaid raceway, the combination of means for supplying lubricant to saidbore of said shaft for delivery to said raceway which comprises alubricant reservoir carrying lubricant at a level below said shaft, astationary porous element arranged for delivery of lubricant bycapillary action to a point adjacent the free end of said shaft, a wickelement having one end thereof immersed in the lubricant n saidreservoir and having a portion thereof engaged with said porous element,means for turning said porous element to vary the point thereon engagedby said wick element, a disc yieldingly urged against a face of saidporous element and against the end of said shaft, and cooperatingformations on said dis and said shaft for pumping lubricant from saiddisc into the bore of said shaft.

13. in a sewing machine having a rotary hook with a rotary component anda stationary component, said hook having a raceway in one of saidcomponents cooperating with a rib on the other of said components, and arotary shaft carrying said rotary component, the combination of meansfor supplying lubricant to said raceway which comprises a lubricantreservoir carrying lubricant at a level below said shaft, porous meansarranged for delivery of lubricant by capillary action from saidreservoir to a point adjacent said shaft for further deliverylongitudinally thereof continuously during operation of the machine to apoint adjacent said rotary component, means comprising passages in saidrotary component for delivery of said lubricant by centrifugal forcefrom said last mentioned point to said raceway, said porous means havinga portion surrounding said shaft, means for varying the rate of deliveryof lubricant to said portion of said porous means, and means for causing14 delivery of lubricant longitudinally of said shaft from said portionof said porous means including a member having flat surface engagementwith said portion and spring means urging said member and said portioninto surface engagement.

References Cited in the file of this patent UNITED STATES PATENTS UNITEDSTATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 2,863,412Remember 3, 1958 John G. Attwood et el,

It is hereby certified that error appears in the-printed specificationof the above numbered patent requiring correction and that the saidLetters Patent should read as corrected below.

Column 1, line 44., for reguirements read M requirements column 2,

line 70, after the" insert end portion of hook. shaft, taken along theand this L'Lii'tl. day or" fir/lay 1.95;

SEAL) ttest: KARL AXLINE ROBERT C. WATSON Attesting Officer Commissionerof Patents

